ANN ARBOR—Research long has shown that socioeconomic status has much to do with how healthy we are, but a study from the University of Michigan reveals that not all races and genders are equally insulated from certain health conditions, even when income and education levels are higher.

The six-year analysis of nearly 37,500 people in the Institute for Social Research Health and Retirement Study examined how income and education influenced depressive symptoms, insomnia, physical inactivity, body mass index and self-rated health.

The study included black and white men and women aged 50 and above.

The general premise is this: Having higher education usually means better-paying jobs, and having more income allows people to take better care of their health.

Dr. Shervin Assari, U-M research investigator in public health and psychiatry, and colleagues found that higher income and education levels did translate into fewer depressive symptoms and better self-rated health across all groups.

But when it came to getting the right amount of sleep, enough physical activity and maintaining a healthy BMI, those with higher income and education levels did not all fare the same when examined by gender and race.

"Higher position in society, determined by higher education and income, reduces depressed and unhealthy feelings, no matter who we are," Assari said. "For maintaining good sleep, physical activity and BMI after age of 50, however, our race and gender make a difference when it comes to the health benefits of education and income."

Specifically, a higher level of education did not protect black man from sustained insomnia, physical inactivity and higher BMI. Income had a protective effect against sustained high BMI among black and white women but not black and white men.

"Although other SES measures such as wealth, employment and occupation also influence health, education and income are considered as the most important social determinants of health," Assari said.

The study, funded by the National Institute on Aging, is published in the Journal of Racial and Ethnic Health Disparities.